The present invention relates generally to locating and mapping network devices in a wireless network, and in particular to facilitating the discovery of a nearest network device via received signal strength at a wireless gateway.
As networks of computing devices and peripherals become more complex and dynamic, it becomes increasingly important for the network structure to be flexible and to be easily updated. To address this challenge, wireless networks have become increasingly popular. Because device additions to a wireless network do not require the addition or rerouting of physical cabling, they are generally more flexible and easily updated than are wired networks. Wireless networks further have the advantage of being able to accommodate transient or mobile users.
One dilemma a network user may face is determining the physical location of a computer peripheral or other network device. As an example, a wireless network user may want to print out a color document from their palmtop computer. The user may want to locate a nearby color printer. While the operating system may be able to provide a list of suitable imaging devices along with textual descriptions of their location, this may not be helpful to the user if they are unfamiliar with the building or complex where the network is located.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative methods for determining the location of a wireless network device.
Methods and apparatus for locating a network device relative to other network devices in a wireless network are described herein. Signal strength in a wireless network is indicative of a distance between a transmitting device and a receiving device. Through use of triangulation of the received signals at one or more receiving devices, the relative location of the transmitting device can be determined. Methods of refining the estimation of the expected location of the transmitting device are further provided. Defining an absolute location for at least one of the devices will permit determining the absolute location of the remaining devices based on these relative locations.
For one embodiment, the invention provides a method of mapping a wireless network having one or more wireless gateways and one or more other network devices. Each wireless gateway is adapted for communication with at least one of the other wireless network devices. The method includes, for each of the other wireless network devices, determining an estimated distance of that other wireless network device from one or more of the wireless gateways based on a received signal strength between that other wireless network device and each of the respective wireless gateways. The method further includes, for each of the other wireless network devices, determining an expected location of that other wireless network device based on the estimated distance of that other wireless network device from the wireless gateways. The expected location is relative to a first network device, such as one of the wireless gateways or one of the other network devices.
For another embodiment, the invention provides a method of locating, in a wireless network, a nearest wireless network device matching a criteria. The method includes determining expected locations of wireless network devices relative to one another based on a signal strength received between each of the wireless network devices and one or more wireless gateways. The wireless network devices and the wireless gateways are part of the wireless network. The method further includes generating a data structure containing the expected locations associated with each of the wireless network devices. The data structure includes supplemental information associated with each of the wireless network devices. The method still further includes searching the data structure for each wireless network device matching the criteria, criteria being compared to at least the supplemental information. The method still further includes identifying each wireless network device matching the criteria and identifying the wireless network device matching the criteria that is nearest a reference point.
For yet another embodiment, the invention provides a computer-usable medium having computer-readable instructions stored thereon capable of causing a processor to perform a method. The method includes determining an estimated distance of one or more first network devices from a second network device based on a strength of a signal received between the one or more first network devices and the second network device. The method further includes determining an estimated distance of the one or more first network devices from a third network device based on a strength of a signal received between the one or more first network devices and the third network device. The method still further includes determining an estimated distance of the one or more first network devices from a fourth network device based on a strength of a signal received between the one or more first network devices and the fourth network device. The method still further includes determining an expected location of each of the first network devices relative to each other based at least on the estimated distances of the first network devices from the second, third and fourth network devices.
Further embodiments of the invention include apparatus and methods of varying scope.